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Nick H. 8,703

Nothing really new since this is just the basic principle of relativity. The faster you go, the more time accelerates.

I believe it's something on the lines of if you travel at the speed of light for one year, 7 years here on Earth would elapse.

So technically that would be time traveling forward with respect to Earth. The key part is the time dilation.

Traveling backwards in time, on the other hand, is physically impossible.

I agree with the first part, there's nothing particularly new in this article as we've known about the theory of relativity for a long time, and with it we've known and tested the time dilation effect.

However, the article points out that there is a possibility of traveling back in time by using wormholes. The only problem is that we can only speculate about the idea, which is as good as saying, "it's not yet possible." Even if wormholes were a portal for time traveling to the past, we've got no way to manipulate it so that it would send us back to a specific time. We'd just have to accept where the wormhole's end point in time is.

I know very little on this, so bear with me...

What you say is the faster you travel, the faster time passes?

So the slower you travel the slower is passes? But that's not true, surely?

No. The theory of relativity states that the closer you get to the speed of light, the slower time passes for you. As the article points out, if you were on a train that got to 99% of the speed of light, you would perceive time as passing at a normal rate, but what is happening is that the time is passing slower on the train than it is for the people at the train station.

So the slower you travel the slower is passes? But that's not true, surely?

No, basically the passage of time will be different for the person travelling close to the speed of light relative to someone standing still on earth, this is time dilation. So if you traveled around the earth at such speeds, for you only a week will have passed, but for everyone moving at relatively much lower speeds around you more time will have passed. The theory is that the closer you get to the speed of light the greater the effect.

edit: spent so long typing, someone beat me to it!

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XerXis 252

XerXis 252

If you want to know more about spacetime, Brian Cox has a nice book that explains it in an easy to understand language.

The fun thing is, not only time changes if you go faster, but also space itself. For example, a lot of people think that travelling to a star that is 5 million lightyear away would take you more than 5 million years if you travel at 99% of the speed light, while in fact it would only take you a few hundred years. Very interesting stuff physics ;)

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neufuse 3,245

send a message wirelessly around the world in under a 100th of a second is physically impossible...... oh wait we do that now... who knows what the future brings, to say something is impossible means you already gave up trying for new inventions...

Astra.Xtreme 2,377

So the slower you travel the slower is passes? But that's not true, surely?

It's kind of an abstract idea, and it gets confusing pretty easily, but the time differential is only measurable when comparing two objects. For instance, if you are in a spaceship traveling at the speed of light away from Earth and then come back, the clock in your spaceship would he ahead of the time on a clock here on Earth. So depending on how you look at it, either time sped up in the spaceship, or time slowed down on Earth. It all comes down to reference.

Another example is that an astronaut in space will age slightly less while in space than people back on Earth. That's due to being further from the center of the Earth and essentially moving at a faster velocity than people on Earth. Gravity may have an effect too. That's pretty much "time dilation" in a nutshell.

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+chconline 158

I don't think backwards time travel is possible. Forward, theoretically yes (Just basic relativity). if in an infinite amount of time from now that backwards time travel is possible, there should be evidence in the past of people from the future coming back. However, there is no evidence of it.

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Malisk 142

Malisk 142

Time travel in the sense that some objects travel slower in time than us happens all the time. GPS satellites regularly need their times corrected because they experience relativistic effects, and we want high accuracy from their clocks. Their clocks simply run slower than ours, but not because they are faulty!

If we didn't regularly correct for the GPS satellites travelling slower in time, the end result would be that navigational errors would accumulate with 10 km per day!

So, in an extreme case, yes, it's both possible and proven that a person can in theory travel very fast around the Earth for a long time and age just 1 year while the entire Earth becomes 100 years older. His friends and relatives would be dead at the time he exits his spacecraft. In practice, though, the energy requirements for this would be absolutely immense and not really workable in any way we can understand today.

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Silver47 54

Traveling back in time isn't impossible, just incredibly hard as you have to move all matter in the universe to its previous point in existence. However that would also effect you, so even if you went back in time within your own life time, you'll be the same age as you had been and completely forgotten you went back in time.

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Joshie 768

I'm not saying I can prove you wrong, but in 1896 the Wright brothers would of thought it was "impossible" to put man in Space, let alone cross the Atlantic ocean.

You're comparing three dimensional travel to not-even-a-dimensional travel. While it's presumptuous to say what the Wright brothers would have thought possible in their day, even the most fantastical forms of travel are at least plausible when they're within dimensions that have already welcomed travel (XYZ). There has, however, never--ever--been any observable evidence, in all of mankind's recorded history and science, that time is a freely traversible dimension.

Traveling back in time isn't impossible, just incredibly hard as you have to move all matter in the universe to its previous point in existence.

That would just be duplicating the past in the future. If I slapped you yesterday and slapped you again today, I didn't send your face back in time.

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Detection 2,255

I don't think backwards time travel is possible. Forward, theoretically yes (Just basic relativity). if in an infinite amount of time from now that backwards time travel is possible, there should be evidence in the past of people from the future coming back. However, there is no evidence of it.

I once worked out why it must be impossible to time travel either way, a similar theory to yours, if it was possible to move back in time, we would already know, and the fact that we don't means it has never been done in the future, which also means, either there is no such thing as the future (yet, only now), or we never work out how to move in time, .... something along those lines

(Disclaimer: The above is a vague memory of a very intelligent thought, back in time)

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Silver47 54

Silver47 54

That would just be duplicating the past in the future. If I slapped you yesterday and slapped you again today, I didn't send your face back in time.

The first part is my point, second part misses it completely .Time is just a measurement of the movement of matter (and also energy), however everything in the universe is moving. Using your example, we would have to move everything back to the point you slapped me. But the process would of also changed our brains to that point as well thus forgetting that you slapped me again the next day followed by going back in time. Think the film Galaxy Quest with the Omega 13 if you ever saw it.

It is only the accepted Beliefs and mental barriers that keeps you locked into this present Time.

Be daring -- accept the challenge. ;)

I once believed, I believed so much that all other beliefs were pushed out of my brain, I was left with only 1 truly amazing 100% brain capacity belief, so I climbed up on the kitchen bench, I stuck my arms out in-front of me and I jumped..

To be fair, I did fly for a short while, but the landing was less comfortable that I believed it would be...

I left the kitchen with the understanding that believing is not really everything